Clutch control mechanism



Oct. 25, 1938. w, PR E T AL 2,134,576

-CLUTCH CONTROL MECHANISM INVENTOR 1 D ATTOR EY Patented Oct. 25, 1938 UNITED STATE s PATIENT OFFICE oLu'rcn con'mor. MECHANISM Harold W. Price and Earl R. Price, South Bend,

Ind.,

assignors to Bendix Aviation Corporation,

South Bend, Ind., a corporation of Delaware Original application November 2'1, 1931, Serial Divided and this application January 18, 1937, Serial No. 121,047

3 Claims. (OI. 192-.01)

This invention relates to power operated clutch controlling mechanism for the standard clutch of an automotive vehicle, such mechanismbeing designed to supplant the manual operation of the clutch and to accurately simulate such manual operation.

An object of the invention is to provide, in a vacuum operated clutch controlling mechanism, means for regulating the disengagement and engagement of the clutch. More specifically, it is an object of the invention to provide valve means, so controlling the influx and eiilux of air to and from the motor of the mechanism, as to insure, at the proper time, a rapid disengagement of the clutch and, what is more important, to provide 20 the aforementioned stages of movement bein for two stages or phases of clutch plate movement in the engagement of the clutch. The total elapsed time in efiecting the engagement of the clutch is thus reduced to a minimum, the first of quite rapid and the latter stage appreciably slower to permit the clutch plates to engage without shock. W

It is the principal object'of the invention to provide a fluid operated automatically operated valve operable to a degree which is a function of the manifold vacuum and serving to control the last or clutch plate contacting stage of clutch plate movement.

Another object of the invention is to variably determine the maximum operation of the aforementioned automatically operated valve in accordance with the gear ratio setting of the I change-speed transmission mechanism to thus predetermine a maximum rate of clutch plate engaging movement for each gear setting.

A further object of the invention is to provide a second bypass or shunt circuit interconnecting the source of vacuum, preferably the aforementioned manifold of the internal-combustion engine, with the aforementioned fluid motor, said circuit to provide an unimpeded fluid transmitting or bleed connection to compensate for leakage in the motor and also facilitate control of.

the clutch engaging operation of said motor.

Other objects of the invention and desirable details of construction and combinations of parts will become apparent from the following description of a preferred embodiment, which descrip: tion is taken in conjunction with the accompanying drawing, in which:

Figure 1 is a diagrammatic view of. the clutch controlling mechanism constituting the invention;

Figure 1A is an enlarged view of pedal operated switch disclosed in Figure 1;

Figure 2 is a longitudinal sectional view through the automatic bleed valve for controlling the second stage of clutch engagement? Figure 3 discloses, in section, the two-way cutofl valve and the solenoid operating means therefor; and

Figure 4 discloses, in longitudinal section, the

the clutch three-way control valve for the clutch operating fluid motor.

- Referring now to that embodiment of the invention disclosed diagrammatically in Figure 1, there is provided a clutch pedal ID, the actuation of which is adapted to control the engagement and disengagement of a conventional clutch, not shown. The clutch pedal is power operated, by

-a vacuum operated fluid motor l2, in such fashion as to accurately simulate the conventional manual operation of the pedal.

- The motor preferably comprises a cylinder i4,

gine throttle 32, by a rod 34, therebeing a degree of lost motion at 36 for a purpose to be described hereinafter. The three-way valve 28, detailed in Figure 4, preferably comprises a casing 38, provided with ports 46, registering with the portions of the conduit 22, and also provided with atmospheric ports 42. A spring pressed valve plunger 44, having a recess 46, is actuated by a flexible connection 48, the latter connected-to an arm 50 rigidly secured to the accelerator or throttle rod 34.

A two-way cut-off valve 52, comprising a casing 54 and a rotatable recessed member 56, is

incorporated in the conduit 24 and is adapted to be actuated by a spring 58 and by a solenoid 60. The solenoid is energized, to close the valve, by the closing of a clutch pedal operated switch 62. The spring 58 serves to open the valve to intercommunicate the motor and manifold, when and if the solenoid is deenergized with the opening of the pedal switch.

way valve 28.

I The invention further includes the incorporation of a check valve 84, incorporated in a bypass or shunt circuit comprising conduit sections 88, 68 and 18, which valve serves to insure operation of the motor, as will be described in greater detail hereinafter.

The most important feature of the invention resides in the provision of an automatically operated clutch controlling bleed valve II. This valve, shown in detail in Figure 2, comprises a casing 12 provided with'ports i4 and receiving conduit sections 18 and 88, said sections being connected, respectively, to the conduit 22 and to the aforementioned shunt conduit 88. A spoolshaped valve member 82 is adapted to be reciprocated in a bore of the casing 12 to register one or more of a plurality of set screw adjustable air bleed orifices 84 with the valve port Hi. The position of the valve 82 is determined by three factors; namely, the manifold vacuum within the compartment in the casing I2 above the upper end of the valve, the atmosphere acting upon the lower end of the valve, and a return spring 88 interposed between the headed end of a valve stem 88 and the casing 12. The valve 82 in its upward position at closed throttle closes oil the port 16, without however covering up the com- -munication between the conduit I8 and ducts 98,

the strength of the return spring 88 acting on the piston valve 82 being calibrated to effect. this position of the valve when the clutch is disengaged. This position of the valve is shown in dotted lines in Figure 2 and insures the aforementioned unimpeded connection between the manifold and motor. The valve casing 12 is provided with the right-angularly extending ducts 88 to provide a supplementary or by-pass connection between the conduits 18 and 88, the rate of air flow via the ducts being adjustable by means of a set screw 92 and also by the degree of pressure within the manifold determined by the mode of throttle operation. Thus ducts 98 provide a permanent connection with the manifold, facilitating the control of the clutch engagement, as will be described in detail hereinafter.

The remaining structural feature of the invention comprises a cam 94, operable by a connection 98 with a conventional transmission or gear shift lever 98, which cam is operative; to determine the completely released position of the spool valve member 82, in accordance with the transmission gear setting. Thus we may, as disclosed diagrammatically in Figure 2, have three settings of the valve member, one for low and reverse gear, one for second gear and one for the high gear setting of the transmission.

Referring now to the operation of the described structure, the parts are shown in their clutch engaged and engine inoperative position in the several figures of the drawing: Thus the accelerator pedal is completely released to insure a closing of the throttle and an opening of the three- The bleed valve H is fully released, and lastly the switch 62 is closed to energize the solenoid 68 and close the two-way or cutoff valve 52.

Upon starting the engine with the throttle closed, there is developed, in the manifold 28, a vacuum of some twenty inches of mercury, which immediately serves, by virtue of the then established differential of pressures, to move the spool valve member 82 to the dotted line or closed position, Figure 2, cutting on port 16 to insure a disengagement of the clutch, and also to evacuate the motor via the conduit 22, valve 28, conduit 66, check valve '84 and conduits 58, I8 and 28. The weight of the atmosphere acting onthe outer end of the piston l8 then effects a disengagement of the clutch, moving the pedal and piston to the dotted line positions of Figure 1. The switch 82 is opened, after the pedal has moved a relatively short distance, thereby permitting the spring 88 to open the cut-out valve 52 and more effectively evacuate the motor to disengage the clutch.

The transmission is then placed in low gear preparatory to starting the car, predetermining the position of the cam member 84 controlled by said transmission.

The accelerator pedal 38 is now actuated, first closing the three-way valve 28 by registering lower port 48 and ports 42 and then opening the throttle to speed up the engine. With the venting of the motor, via the three-way valve, open cut-out valve 52 and interconnected conduits, the piston and connected clutch pedal move relatively rapidly to engage the clutch, this by virtue of the relatively rapid influx of air to the motor. However, when the clutch pedal reaches a position just prior to the actual contacting of the driving and driven clutch plates, the switch 82 is closed to cut off the aforementioned influx of air via the three-way valve 28. Thereafter the air is bled into the motor via the openings 84 in the bleed valve II, the degree of said air bleed being a function of the manifold vacuum which controls the position of the spool member '82 and also a function of the transmission settingwhich determines the maximum rate of bleed for a given transmission setting. Air is also bled into the motor from the manifold via the ducts 98 in the bleed valve, the rate of influx of air from this source being a function of the degree of manifold vacuum as determined by the control of the throttle. It will also be appreciated that, should the accelerator be depressed only sumciently to operate the valve 28 without opening the throttle, this operation being permitted by virtue of the slot 38, the engagement of the clutch will be stopped just at the point of clutch engagement. This operation is inherent in the mechanism in view of the function of the valve 52 as described above.

Should the accelerator be held in this position for any appreciable time, the permanent vacuum connection with the fluid motor l2 via the ducts 98 and conduits 18 will result in a sufficient evacuation of the motor to again disengage the clutch. However, if the clutch is disengaged to the point of breaking the switch 62, then the valve 52' will be again operated to connect the motor to the atmosphere via the valve 28 and the clutch will be reengaged. This oscillating or so-called hunting action at the clutch engaging point will continue indefinitely, should the accelerator remain in the aforementioned partially open position.

Upon continued depression of the accelerator, however, the throttle is opened, as described above, to open one or more of the bleed ports 84 and initiate a completion of the engagement of the clutch at a rate determined by the degree and/or mode of throttle manipulation. neuvering the car from a parked position, it is often necessary to slip the clutch and very carefully control its engagement. This may be 'accomplished with the mechanism of the invention, inasmuch as the accelerator may be released to a point where the air evacuated from the clutch motor via the ducts 98 just balances the influx of air to the motor via the bleed ports 84,

In mathus maintaining the clutch engaged at a fixed point or constant load: with further release of the accelerator to completely close the throttle without operation of the valve 28, the aforementioned arrest point may again befound. Thus it is obvious that with careful manipulation of the accelerator the clutch may be successively engaged and released at will to facilitate maneuvering of the vehicle. ,The mode of clutch engagement is controlled completely by the mode of operation of the accelerator.

There is thus provided a power operated mechanism, automatic in its action, which accurately simulates a manual control of the clutch. The

automatic operation of the bleed valve insures a rate of clutch plate contacting movement in accordance with the mode of operation of the engine throttle, and the additional control of the bleed valve by the transmission setting provides a check upon the operation of said valve, which, in a measure, renders the mechanism fool-proof. The invention heretofore described is disclosed in our Patent No. 2,086,576 dated July 13, 1937, this application constituting a division thereof.

While one illustrative embodiment has been described, it is not our intention to limit the scope of the invention to that particular embodiment,

for otherwise than by the terms of the appended claims.

We claim:

1. In an automotive vehicle provided with a clutch and a change-speed transmission mechanism, power means for operating the clutch including a bleed valve mechanism, said mechanism comprising a valve casing having a plurality of vent ports and a port adapted to be connected with a pressure differential operated motor, a reciprocable valve member housed within said casing and adapted to interconnect said motor port with one or more of said vent ports, and means secured to said valve member serving as a stop member for limiting the movement of said valve member in accordance with the setting of the transmission.

2. In an automotive vehicle provided with a clutch and a change-speed transmission mechanism, power means for operating the clutch including a bleed valve mechanism, said mechanism comprising a valve casing having a plurality of vent ports and a port adapted to be connected with a pressure differential operated motor, a reciprocable pressure differential operated valve member housed within said casing and adapted to interconnect said motor port with one or more of said vent ports, and a stem secured to said valve' member serving as a. stop member for limiting the movement of said valve member in accordance with the setting of the transmission.

3. In an automotive vehicle provided with a clutch and a change-speed transmission mechanism, power means for operating the clutch including a bleed valve mechanism, said mechanism comprising a valve casing having a plurality of vent ports and a vport adapted to be connected with a pressure differential operated motor, a reciprocable pressure difierential operated valve member housed within said casing and adapted to interconnect said motor port with one or more of said vent ports, and a stem secured to said valve member and extending from said valve casing, said stem serving as a stop member for limiting the movement of said valve member in accordance with the setting of the transmission.

HAROLD W. PRICEL EARL R. PRICE. 

